title: Chorion patterning: a window into gene regulation and Drosophila species' relatedness.
abstract: Changes in gene regulation are associated with the evolution of morphologies. However, the specific sequence information controlling gene expression is largely unknown and discovery is time and labor consuming. We use the intricate patterning of follicle cells to probe species' relatedness in the absence of sequence information. We focus on one of the major families of genes that pattern the Drosophila eggshell, the Chorion protein (Cp). Systematically screening for the spatiotemporal patterning of all nine Cp genes in three species (Drosophila melanogaster, D. nebulosa, and D. willistoni), we found that most genes are expressed dynamically during mid and late stages of oogenesis. Applying an annotation code, we transformed the data into binary matrices that capture the complexity of gene expression. Gene patterning is sufficient to predict species' relatedness, consistent with their phylogeny. Surprisingly, we found that expression domains of most genes are different among species, suggesting that Cp regulation is rapidly evolving. In addition, we found a morphological novelty along the dorsalmost side of the eggshell, the dorsal ridge. Our matrix analysis placed the dorsal ridge domain in a cluster of epidermal growth factor receptor associated domains, which was validated through genetic and chemical perturbations. Expression domains are regulated cooperatively or independently by signaling pathways, supporting that complex patterns are combinatorially assembled from simple domains.
authors.affiliation: Center for Computational and Integrative Biology, Rutgers, The State University of NJ.
authors.forename: Matthew G
authors.initials: MG
authors.lastname: Niepielko
authors.forename: Robert A
authors.initials: RA
authors.lastname: Marmion
authors.forename: Kenneth
authors.initials: K
authors.lastname: Kim
authors.forename: David
authors.initials: D
authors.lastname: Luor
authors.forename: Chelsea
authors.initials: C
authors.lastname: Ray
authors.forename: Nir
authors.initials: N
authors.lastname: Yakoby
mesh_terms: D000818:Animals; D019521:Body Patterning / Q000235:genetics; D003001:Cloning, Molecular; D004330:Drosophila / Q000145:classification* / Q000235:genetics*; D004331:Drosophila melanogaster / Q000145:classification / Q000235:genetics*; D004527:Egg Proteins / Q000235:genetics* / Q000378:metabolism; D066246:ErbB Receptors / Q000235:genetics / Q000378:metabolism; D019143:Evolution, Molecular; D018507:Gene Expression Regulation, Developmental; D009866:Oogenesis; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D015398:Signal Transduction
chemical_list: D004527:Egg Proteins; C015753:chorion proteins; D066246:ErbB Receptors
keywords: EGFR signaling; eggshell; oogenesis; tissue patterning